The present invention relates to a socket having means for no-load engaging by and releasing of an IC package, and more especially to a socket including a base plate having at least one row of contact receiving vertical openings each accommodating a contact engageable with a lead wire, a movable plate having at least one row of through openings each corresponding to a vertical opening and passing a lead wire of the IC package which is placed on the movable plate and means to move the movable plate between a lead wire released release position and a contact engaging position.
Such a socket is known from Japanese Utility Model Application Publication No. 49978/1977. The movable plate of the socket supports all the wire leads of an IC package in lead wire receiving through holes, and when the movable plate is moved from the release position to the contact engaging position, a lateral urging force is applied directly to the side surfaces of the lead wires and the movable plate is moved parallel with the direction of the row of the vertical openings, i.e., parallel to the direction of the rows of contacts.
Japanese Laid-Open Patent Publication No. 88987/1978 (U.S. patent application Ser. No. 755759, Mark Auriana) also describes a socket of generally similar construction to that of the above described publication.
Because the movable plate moves in the direction of the rows of contacts, there must be a space to allow movement of the corresponding lead wire between the release position and the contact engaging position in each vertical opening of the base plate. As is well known, such an IC package has many lead wires in a row with very narrow spaces therebetween. Thus, the distance between adjacent vertical openings receiving the dead wires is also very small. Because the wall between the vertical openings is also very thin, there is little space to allow movement of the movable plate between the release position and the positive contact engaging position. Thus, there are serious problems in the design of the contact, positive release and positive engagement and bending of a lead wire relative to an adjacent lead wire. These problems affect the design of the IC package and an LSI package, both of which tend to have a large number of lead wires so that it is desirable to reduce the distance between adjacent lead wires.
In the above-mentioned Japanese Utility Model Publication, the movable plate has very small through openings to pass the lead wires and engages the side surface of the lead wire. Thus, the lead wire tends to bend toward the adjacent lead wire due to the side pressure. When one or more lead wires are bent, the IC package is difficult to reinsert, as all the lead wires must align with the through openings of the movable plate.